User blog comment:Demon Killer/The Angels and Demons/@comment-976055-20111003191422

The fact that Dante lives among humans could be some otherworldly law that forces him between the world of the devils and the world of the angels - Earth. It's rather simple, but it makes sense. He's a hybrid of both, so he isn't really accepted into either world, and is thus stuck in a sort of middle-ground, alongside humanity.

Couple that with the idea that demons are constantly trying to kill him, I can see Dante being really angry towards them, and inadvertently helping Angels :p I have a feeling that hooded girl talking with Dante in the beginning of the TGS Stage Demo was an angel...